主动探测型时间反转电磁波聚焦

为扩展时间反转理论在电磁领域的应用,提出了一种基于主动探测的时间反转电磁波聚焦方法.该方法是通过时间反转目标的反射波并在目标搜索域内进行能量搜索来实现重聚焦的.首先,收发合置传感器阵列的一个天线阵元向目标区域发射电磁波信号,该电磁波信号遇到目标后反射,反射后的电磁波被各天线阵元接收并记录.当所有阵元全部完成上述发射和接收过程后,将每个阵元中得到的所有信号相加,并进行时间反转.然后,将各阵元时间反转后的信号虚拟重发到目标域中,则信号能量会在目标处实现重聚焦.根据电磁波的传播特性,给出了主动探测型时间反转聚焦的原理及方法.最后,通过仿真实验验证了主动探测型时间反转可以有效实现电磁波重聚焦的特性.

Electromagnetic wave focusing of active detected time reversal

In order to extend the application area of time reversal theory in the electromagnetic field, a method for electromagnetic wave focusing based on the active detected time reversal theory is proposed. This method accomplishes the refocusing of signal energy by time reversing the reflected waves of targets and searching signal energy in the search area. Firstly, an antenna element in the transducer array emits electromagnetic waves to the target area. And this signal is reflected by targets, and every antenna element receives and records the reflected signals. When the process of emitting and receiving is finished by all antennas, all signals received by an antenna are added and time reversed. Then, retransmitting the time-reversed signals of every antenna to the target area virtually, and the signal energy is refocused in the direction of targets. Based on the propagation characteristics of electromagnetic waves the fundamentals of and the algorithm for active detected time reversal refocusing are given in this paper. Finally, the characteristic that the proposed method can accomplish electromagnetic wave refocusing effectively is validated via simulation.